1. Field of Invention
This invention relates in general to railway cars and more particularly, to an improved cable/strap assembly for center beam flat cars used to tie down loads.
2. Description of the Prior Art
At present, lumber and other construction material is conventionally transported by railroads in center beam/center partition railcars. The center beam/center partition design permits the construction of lightweight cars with long spans between the bulkheads at each end. Generally, the center beam/center partition flat car includes a center beam assembly having a plurality of truss vertical columns situated along the longitudinal center sill. The upper ends of the truss vertical columns are coupled to an upper beam structure that extends between the bulkheads. Lumber or other lading is carried on the floor deck on opposite sides of the truss vertical columns. The lumber and the like that is transported in center beam/center partition flat cars is commonly made up of equal length pieces banded together in modules. The lengths of the modules range from eight to thirty-two feet in increments of two foot lengths and nominal four foot widths. The actual width of lumber modules varies according to nominal dimensions of 2".times.4", 2".times.6", 2".times.8", 2".times.10", and 2".times.12". The height of each module is a constant twenty-four inches. The modules of lumber can be stacked up to five high on both sides of the center beam/center partition cars.
The modules or other load are presently retained in position on the flat car by an assembly that includes a plurality of elongated cables, straps or chains which extend from winches mounted on the side sills on each side upward along the outer side of the load at a number of longitudinal positions. The upper free ends of the elongated retention members are secured above the load in keyslots or other retention means provided on the upper beam assembly of the center beam/center partition flat car. The cables and the like thereby primarily secure the outer lateral wall and top of the load on the flat car during transport.
Several problems are associated with the attachment of the ends of the elongated members at positions above the load as in the known technique of securement. The necessity of attachment of the free end of the cable or strap above the modules after loading, or alternatively to release the secured free end for unloading, is inconvenient and time consuming. The normal procedure is for personnel to climb the flat car after loading and attach the free ends of the cable or strap to keyslots provided in the upper beam assembly. The tension on each of the elongated members is thereafter tightened by the winches from ground level after the free ends are retained. Similarly, unloading requires release of the free ends of the cable or strap, again requiring personnel to climb the center beam/center partition car. It should be apparent that the winches are not positioned at an efficient location relative to the keyslots or other securement means in known arrangements. In addition, the secured cable or strap in the prior art only overlaps a portion of the load along the outward face and across the top without achieving optimum confinement. One or more of the cables or straps in the prior art designs are also frequently left dangling from the winches beyond the side of the car, after the free end is released, particularly after unloading. The presence of unrestrained straps, cables, or chains hanging from the flat car presents a potential safety hazard and damage to the individual elongated retention members. Therefore, it is desirable to provide an improved strap/cable assembly for center beam/center partition flat cars that eliminates the foregoing problems.